1. Field of the Invention
The present invention relates generally to lighting fixtures and more particularly to lighting fixtures that are recessible into an opening formed in a ceiling.
2. Description of the Prior Art
Elongated lighting fixtures for receipt of fluorescent tubes have become quite popular. It has long been the practice of manufacturers to construct housings for such fixtures by extruding aluminum channel shapes having a thickness on the order of 0.0078 inches. The extruded channel shapes are typically cut to length, anodized, holes drilled and end caps secured by pop rivets or screws.
More recently, fixtures of this type have gained popularity in the recreational vehicle market. In this market, weight and economy become a major factor. Thus, many efforts have been made to minimize the weight of such fixtures and to minimize the number of components required for assembly thereof as well as the cost of manufacturing such components. Also, in the recreational vehicle market, lighting fixtures which are, to a major extent, recessible into the ceiling or side wall of a recreational vehicle, leaving only an opaque or translucent diffuser element and a border portion area, exposed to the viewer have also gained popularity. One such lighting fixture incorporates a channel shaped extruded aluminum pan defining a housing which has downwardly projecting opposed sides which, at their free extremities, are formed with turned back confronting flanges defining confronting grooves for receipt of the opposed terminal edges of a channel shaped diffuser lens. End caps are then riveted or secured to the opposite ends of the housing. A device of this type is shown in U.S. Pat. No. 4,698,733 to Griffin and assigned to the assignee of the instant application.
Such devices, while enjoying substantial success commercially, suffer the shortcoming that the extruded housing consumes considerable metal, typically has a relatively high profile requiring substantial clearance for recessing, adds substantially to the weight of any vehicle in which it is installed and must be anodized after extrusion.
Other lighting fixture designs for receipt of elongated tubes have formed with channel shaped housings of relatively complex cross sectional construction and include opposed mounting flanges for receipt of the terminal edges of the flexible walls of a diffuser. A device of this type is shown in U.S. Pat. No. 3,159,352. Such devices are relatively expensive to form, require a fairly substantial amount of material to form screw tracks for receipt of end cap mounting screws and mounting flanges of sufficient structural rigidity to form the grooves for receipt of the opposed sides of the diffuser. Such housings also often are of such depth or thickness as to be somewhat limited to installations where substantial clearance is afforded behind the ceiling or wall in which it is to be mounted.
Elongated mounting fixtures have been proposed which include channel shaped housings onto which channel shaped diffusers are mounted. End caps are then received over the opposed ends thereof of such housing and diffuser. A device of this type is shown in U.S. Pat. No. 2,694,775 to Florence. Such lighting fixtures, while providing adequate mounting and lighting capabilities, are relatively expensive to manufacture since mounting of the diffuser incorporates relatively sophisticated construction thereby adding to the expense of manufacture. Thus, there exists a need for a recessed fluorescent tube lighting fixture which is of relatively simple and straightforward construction, provides economical to manufacture and which will provide for an aesthetically pleasing appearance and for reliable mounting of a diffuser lens.